[LEAPSECS] Lets get REAL about time.

[Poul-Henning Kamp]

In message <4F19885C.3090502 at sfr.fr>, mike cook writes:


>> Modern CPUs clock around 4GHz, multiplying by 1000 for resulution we

>> find that we need 42 bits after the binary point.

>

>Solaris already has 64 bit quantities for time operations. From their doc:

>

>"time_t, and its derivative types struct timeval and timespec_t now =

>

>contain 64-bit quantities"

>

>Aren't you reinventing the wheel? Its open source, so just borrow it.


No, time_t is entirely in front of the binary point:  It counts seconds.

We need something which will also do the fractions of seconds and without
braindamage of the "struct timeval" type.


>> Our new timecale should run on the TAI timescale which does not

>> have leap-seconds or any other artifacts, and library functions can

>> convert that to UTC time, civil time etc, using a leap-second table

>> which can be updated as and when leap-seconds gets announced.

>

>Fine, but if TAI is going to be adopted anytime as the standard of time =

>dissemination, nobody is going to be announcing leap seconds, UNLESS, =

>parallel time scales spring up.


PTP already uses TAI

TAI can be derived from UTC, GPS and other broadcast timescales, so
availability is fine.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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